Question

Ethylene diamine tetra-acetic acid (EDTA) is a water soluble compound that readily combines with metals such as calcium, magnesium, and iron. The molecular formula for EDTA is C10N2O8H16. One EDTA molecule complexes (associates with) one metal atom. A factory produces an aqueous waste that contains 20 mg/L calcium and collects the waste in 44-gallon drum. What mass of EDTA would need to be added to each drum to completely complexes all of the calcium in the barrel?

Answer 1

Answer:

There should be added 24.33g of EDTA

Explanation:

EDTA + Ca2+ → Ca(EDTA)

MM of EDTA = 292.24g/mole

MM of Ca2+ =40g/mole

An aqueos waste contains 20 mg/L Calcium,  and collects the waste in 44 gallon drums.

The concentration of Ca2+ ions = 20mg/L = 0.02g/L

We know 1 gallon = 3.785L

The mass of calcium ions  is in 44 gallons

⇒44 gallons = 3.785 * 44 = 166.54 L

Since the aqueous waste contains 0.02g/L calcium

in 44 gallons or 166.54 L ⇒ 166.54 * 0.02g = 3.308g

MM of Ca2+ = 40g/mole

⇒40g of Ca2+ reacts with 292.24g of EDTA

⇒ (292.24/40 ) * 3.308g = 24.33 g

There should be added 24.33g of EDTA